Variable-exhaust mechanism.



PATENTED JULY l, 19N.

BEST MA1LN3\.L=.l @Op 0.1.. PAGBN'HART'. VARIABLE EXHAUST MSCHAMSM.

AYPLIGATIN FILED 00T. 12, 1904.

BEST AVAlLABLE CO2" UNITED STATES Patented July 18, 1905.

PATENT OEEICE.

TI-IIRDS TO DAVID R. TENNILLE, GEORGIA.

THOMAS AND JULIUS BASHINSKI, JR., OF

VARIABLE-EXHAUST MECHANISNI.

'SPECIFICATION forming part of Letters Patent No. 794,881, dated July18, 1905. Application filed October l2, 1904. Serial No. 228.213.

To {LZZ whom, it may concern;

Be itknown that I, CHARLES L. PAGENHART, a citizen of the United States,residing at Tennille, in the county of Washington and State of 5Georgia, have invented certain new and useful Improvements inVariable-Exhaust-Mechanism for Application to Steam-Engines WhereverSuch a Device is Desirable to be Employed; and Ihereby declare thefollowing to 1o be a fulhclear, and exact description of thesama-reference being had to the accompanying drawings, in which-- Figure1 is a vertical central section of a mechanism embodying my invention,shown in connection with the exhaust-column and exhaust-columnbridge of a locomotive to control the 'exhaust thereof. Fig. 2 is anenlarged detail section of a portion of the exhaust-column, showing theeolumn-bridge-ad- 2O justing cam mounted therein, and a portion of onesection of the adjustable column-bridge. Like symbols refer to likeparts wherever they occur.

Myinvention relates to that class of devices especially designed togovern or control the exhausts of steam-engines, but generallyapplicable for exhaust purposes under similar conditions, and has forits objects to produce a mechanism which shall automatically increase ordecrease the draft accordingly as the steam-pressure may fall below orrisc above the normal and to generally reduce the back pressure, as wellas prevent the back pressure of one cylinder upon an'opposite cylinder,3 5 thereby saving a large percentage of the fuel ordinarily necessary,while at the same time producing a more eiiicient engine and locomotiveof increased and more uniform speed and power. Hitherto in theconstruction of va- 40 riahle-exhaust mechanism designed to accomplishthese several before-noted objects cones or other devices adapted tovary the area of the opening in the exhaust-nozzle have been commonlyemployed, or flap or other valves have been used; but a constructionsuch the former type impairs the eflicient working of the engine byreasonof the back pressure created by the obstruction thus placed cen-`haust-oolumn preferably slightly` above trally of the exhaust-nozzle,and devices of the latter type generally produce cross-firing of theexhaust in the stack and soon become inefficient by reason of theconstant vibration and oscillation to which they are subjected when inservice.

To accomplish the before-noted objects and to overcome the objectionspointed out, I combine with the exhaust-column of an engine anexhaust-column bridge separating the cylinder exhaust-ports, said bridgehaving upwardly-diverging sides and having its upper extremity adjacentto the choke of the exthe same.

A second feature of my invention resides in so arranging andconstructing the exhaustcolumn bridge that the exhaust area of the gexhaust-column may be varied by a change in the form of the saidexhaust-colummbridge'.

A third feature of my invention resides in the means for automaticallyadjusting and controlling the exhaust-column bridge, said meanscomprising a` plurality of differentlygraduated 'valvesinterposedbetween a common source of pressure and a cylinder the movement of whosepiston actuates the""ad justable exhaust-column bridge by any suitableconnections.

A fourth feature of my invention resides in an automatic exhaust-valvemechanism for the cylinder whose piston actuates the exhaustcolumnbridge.

There are other minor features of invention" residing in particularcoi'nbinations and elemental constructions, all as will hereinafter morefully appear and be particularly pointed out in the claims.

I will now proceed to describe my invention more fully, so that othersskilled in the art to which it appertains may apply the same.

lrVhile I have illustrated my devices as applied to a locomotive, yet itwill be Linderstood that my invention as pointed out inthe claims is ofbroader scope and may be applied to any engine wherein a forced draft isdesirable, and similarly the automatic means BEST AVAlLABLE CO?" forcontrolling the form and size of the adl justable column-bridge and themeans for automatically controlling the exhaust of the cylinder whichactuates the column-bridge are of more general application in the arts.

In the drawings, A is the smoke-box of a locomotive, having therein anexhaust-column B, the lower end of which is secured to thecylinder-saddle (not shown) connected to the cylinders (not shown)through usual and wellknown exhaust ports or in other suitable manner.The exhaust-column B is preferably gradually contracted in area to thechoke l thereof and from thence is preferably increased in area for atleast a part 2b of its remaining length, the converging Walls of thelower portion of -said exhaust-column B, if prolonged, preferablymeeting at a point in the longitudinal axis of the stack (not shown) andadjacent to the lower end' of the latter; but, if desired, any othersuitable form of exhaust-column may be employed.

Within the exhaust-column Band interposed between` the exhaust-portsconnected to the cylinders in such manner as to divide said exhaust-column into two independent compartments is the exhaust-column bridgeC, which is -preferably constructed with upwardly-diverging sides andwhich terminates at oradjacent to the choke 1b of the exhaustcolumn B,the outwardly flaring or diverging sides directing the exhaust centrallyupward through 4the column and counteracting the tendency ofthe-exhaustesteam to cross to the opposite Side ofthe column and tocreate back pressure on the opposite cylinder, thus 'preventing anydecrease of the effective pressure upon suoli. opposite cylinder. Bythis means also the exhaust-steam from one cylinder does not cross thepath of the exhauststeam .from the other cylinder, and the swirl.

ing of the steam, which is so detrimental to a perfect draft and a freeexhaust, is obviated. The exhaust-column. bridge C, which, as willhereinappear, is a means for regulating the draftin the stack, ispreferably constructed of a plurality of resilient sections 1c 1, whichare bolted or otherwise secured to the columnbridge base 2c, the latterbeing rigidly fas-- tened to the base of the exhaust-column intermediatethe cylinder exhaust-ports leading thereinto, said resilient sections 1c1c having their upper ends bent inwardly to overlap and closely engageeach other, thus forming a closure for the top of said adjustablecolumn-bridge and permitting a relative movement toward and from eachother of the two sections. If desired, the edges of the resilientmembers 1 lc may be provided with spring-pressed packing-strips whichengage the fiattened walls 3" 3" of theexhaust-column B, thus preventingany possible leakage from one exhaust-compartment to the otherexhaust-compartment of the said exhaustcolumn.

\Vhile I prefer to form the sections lC 1 of the adjustableexhaust-column bridge C of resilient material such that the saidsections will always have a tendency to approach each other, yet it isobvious that this function may be accomplished by a spring interposedbetween the sections and bearing upon each. It is apparent also that thesections 1e l'3 of the adjustable exhaust column bridge may beconstructed of a single piece of metal formed into the proper shape.

The cam-shaft D, to which is secured the cam E, is -iournaled in theexhaust-column B near the choke l" thereof, one of its ends engaging thecorresponding socket 4f" of the said column B, (see Fig 2,) the otherend passing through a thimble 1d, which engages the interiorly-threadednipple 5b of the exhaust-column; but, if desired, other means may beemployed for this purpose.

The cam or double eccentric E, which is interposed between the resilientsections 1I 1c of the exhaust-column bridge C and is a means both foradjusting-the said sections lC l and retaining them in an adjustedposition, is preferably formed with a square aperture running axiallytherethrough for engaging a correspondingly-formed portion of thecam-shaft D, said cam being thereby fixed to its shaft in respect of anyrelative turning movement; but other well-known means-as, for example, akey or spline-may be employed to secure the cam to its shaft.

Rigidly attached in any suitable manner to that end of the cam-shaft Dwhich passes through the exhaust-column B is the lever or crank F, saidcrank having its opposite end flexibly secured to the reach -rod Gr by aknuckle-joint or other connection of like character.

For the purpose of readily adapting the device to different locomotives,as well as to relatively adjust the parts and to readily assemble thesame, I prefer to form the reach-rod G of a plurality of sections l 1"',connected by a turnbuckle 2, the latter being engaged by thejam-nnt 3g,which restrains any movement of the latter, and thus affords a means forsecuring the sections of the reach-rod in a fixed relation;` but othermeans whereby the reach-rod may be rendered extensible in character maybe employed, or the reach-rod may be constructed as an integral member.

Bolted or otherwise secured upon the exterior of the smoke-box is abracket H, preferably com prising a baseplate l, con forming to thatpart of the locomotive to which it is applied, and an open yoke 2", thesaid baseplate and yoke being each provided with a stuffing-box of anyusual or suitable construetion either made integral therewith ordetachable therefrom.

fliile l prefer to locate the bracket ll, which forms the-,support forthe cylinder con- IOO IIO

trolling the exhaust-column bridge C, con-30 tiguous to the sm oke-box,yet said bracket and the mechanism carried thereby may obviously belocated in any other suitable position upon the engine or locomotive.

Secured to the bracket H by bolts passing through an angular fiange orin other suitable manner is the cylinder K, the head 1k whereof isprovided with ahand-wheel 2k and attached threaded rod 3, havingthreaded engagement with the said cylinder-head 1k, by which means thelength of stroke of the piston or other movable member L Within thecylinder K is limited and by which primarily the minimum area of theexhaust-opening of the exhaustcolumn is regulated through the cam ordouble eccentric E, which controls the relative 'position of theresilient'members 1c 1c, constituting the adjustable exhaust-columnbridge C; but, if desired, other meansrfor regulating the minimum areaof the exhaust and the corresponding maximum separation of theadjustable members of the said column-bridge may be employed.

Vithin the cylinder K isa piston L-ovair'iywell-known orsuitableconstruction, the piston-rod whereof is exibly connected to thereach-rod G, preferably by a knuckle-joint, said piston-rodl passingthrough and being guided-by the stuing-boxes of the vbracket H.

The cylinder K is provided with ports l4" 5k for the admission of steamto the cylinder on opposite sides of the piston and isalso pref-v erablyprovided with corresponding leakage-f. grooves orexbaust-ports 6k7kofcomparatively-'g small area for the escape of steam and of water ofcondensation; but, if desired, automat-- ically-controlledexhaust-valves may be substituted for such leakage grooves or ip orts,or.

bib-cocks or other valves may be .employed in addition to such leakageports orvalves.

When automatic exhaust-valves arel desired to control theleakage-grooves or exhaustports 6k 7k of main cylinder K, I preferablyemploy the means therefor devised by me and i shown in thedrau-'ings-A-that is .to say', I secure to the cylinder K adjacent or inline with the exhaust-ports 6k 7k valve-cases or supplemental cylindersW W', each of which is connected with the opposite end of main cylinderK by a live-steam port or passage 8 (or 8W) and provided with anexhaust-port 9, (or 9`v,) and within each of said valve-cases I providea piston X (or X') or diaphragm, which is connected with the adjacentvalveY, (or Y',) which controls the exhaust-port 6k, (or 7k,) so thatwhen there is no pressure or the pressure is uniform on both heads ofpiston L of main cylinder 'K said valve Y (orY) remains.

seated; but as soon as the pressure becomes greater upon one headof thepiston than on the other the said pressure will act through the port 8(or 8W) upon piston "X (or X) to open valve Y, (or Y.) The unseating ofvalve Y at once puts exhaust-port 6 in communicaessi AvAiLAeLE coP tionWithexha'ust-port 8, while the unseating of valve Y puts exhaust-port 7kin communication with exhaust-port 9. It is evident that this automaticexhaustmechanism is applicable tothe control of the leakage or exhaustports of fluid-pressure cylinders in general.

VMounted upon the-,cylinder K in any snitable manner, as by beingthreaded thereinto, are the diaphragm-bodies M and N,the same havingvalved passages therein communicatingwith the ports ik 5", respectively,and also having apertures to receive a pipe or other means fortransmitting pressure to the diaphragme O P, as will hereinafter appear.

'Mounted within the respective diaphragmbodies M and N, and preferablysecured therein by means of the spring-cases QQ, which are or may bethreaded to engage corresponding threads of said diaphragm-bodies arethe diaphragms O and P, the latter` being formed, of any suitableflexible material, preferably. Vcopper or brass.

Secured to the diaphragm O is the highpressure valve o, which is adaptedto be lifted from its seat Within the diaphragm-body M to admit steam.or other Huid pressure to cylinder K through. the port 4E Whenthesteampressure in the boiler rises above the limit at which saidhigh-pressure Valve o is setto open, the low-pressure Valve p, located;within the diaphragm-body N, being similarly secured to `its :diaphragmP, but being adapted to open -toadmit pressure to thecylinder K throughthe port-5k When the- -steam-pressure in the yboiler falls below.thepressure at which said -last-namedvalve is set to open. '7 f l In lieuofrthe diaphragms I may. substitute pistons lWorking in the spring-casesQ Q; but a construction employing such diaphragms is preferable, astlie`opening of the attached valves is thus limited in a very simple mannerand a tight steam-joint is readily secured.

- Preferably housed within spring-cases Q, Q

are the springs S S, each of said springs be' ing interposed between oneof the diaphragme O P and one of the adjusting-nuts R It, by l which thepressure of such springs upon the diaphragms and attached valves may begraduated.v It will be noted that the springs S S are the preferredmoans for mai ntaining a constant pressure of predetermined amount uponthe ,respective valves; but other means for IOO IIO

this purpose may he employed, or under suitable conditions of operationthe diaphragms themselves vmay be made of the desired difference instiffness.

The interior chambers of the diaphragmbodies M and N, which open intothe cylinder K, are connected to a common source of pressure through thepipe 'l.`v, which connects the diaphragm-bodies and the pipe V, which issupplied with steam at l. oilei'-\;iressurc; but other means may beadopted for this puipose,

if desired-as, for example, each diaphragmbody may be independentlyconnected to the boiler-pressure.

The construction being substantially such as hereinbefore pointed out,the device will operate as follows: rIhe mechanism having been assembledand placed in position on the locomotive, the turnbuckle 2g having beenmanipulated tomake the reach-rod G of proper length, the desired minimumexhaust area of the exhaust-column at the choke having been fixed byproperly adjusting the screw-rod 3k by means of the hand -wheel 2k, andthe adjusting-nuts R R having been operated to produce pressure upon therespective valves corresponding to the pressures at which it is desired.they shall open to admit steam to the cylinder K, the live steam fromthe boiler will pass through the pipes V and T to the interior chambersof the diaphragm-bodies M and N. If at this time the steam-pressure iswithin the limits of variation it is desired to allow,

such variation being represented by the difference between thespring-pressure upon the high-pressure valve 0, which is designed toopen when the steam-pressure exceeds the desired upper limit, and thespring-pressure upon the low-pressure-valve 10, which is designed toopen when the steam-pressure falls below the desired lower limit, thenboth highpressure valve o and low-pressure valve p will remain closed,since the pressure of steam is insuflicient to overcome either spring,and the adjustable exhaust-column bridge will be unaffected and willmaintain the exhaust area at the choke of the exhaust-column which ithas "been designed or adjusted to have under normal conditions. If nowthe steam-pressure should rise above lthe upper limit at which'thehigh-pressure valve 0 is set, such excessive pressure acting upon thediaphragms O and P through the pressure-pipes V and T will overcome thespring-pressure upon the diaphragm O, causing the latter and theattached valve 0 to rise, thus admitting steam to the cylinder K throughthe port 4k, and the presl sure entering the main cylinder K throughVthe port Ik will pass through that end of-the cylinder and through port8 to valve-case or supplemental cylinder W and unseat exhaustvalve Y,thus opening the leakage-port 7k to exhaust-port 9. During this time thesteampressure upon the diaphragm P is greater than the spring-pressurethereon, and the low-pressure valve p consequently remains closed. Itthus results that the piston L is moved in a direction to slightlyrotate the cam E and permit the resilient sections lc l of theexhaust-column bridge to more closely approach each other, therebyincreasing the exhaust area at the choke of the exhaust-column, and thuspermitting a freer exhaust, while at the same time decreasing the draftin the stack. Vhen the pressure of steam in the boiler has dropped byreason of the de- BST AVAlLABLE COF" creased draft until it is below thepressure at which the high-pressure valve 0 is set, such Valve 0 isclosed through the spring acting thereon. If now the steam-pressure inthe boiler should fall below the limit at which the low-pressure valve pis designed to open, such steam-pressure acting through the pipes VandTwill be communicated to the diaphragms l O and P and will beinsulhcient to overcome the springpressure maintaining the highpressurevalve closed, but will, permit the spring-pressure upon the low-pressurevalve p to open said last-named valve, as shown in Fig. 1, to admitsteam to the cylinder K through the port 5k,which steam will also passthrough port or passage 8W to valve-case or supplemental cylinder W andunseat the exhaust-valveY, thus opening the leakage-port 6k to theexhaust-port 9W. At the same time the piston L is moved to cause aslight rotation of the cam E, which results in a spreading or separationof the sections 1c l of the exhaust-column bridge, thus decreasing thearea of the exhaust at the choke of the exhaustcolumn by changing theform of said columnbridge, andV thereby increasing the draft. When thesteam-pressure` in the boiler has risen above the pressure at which thelow-- pressure valve is set, such pressure thereupon closes said valve.v

While l have illustrated and described a particular mechanism forautomatically actuating my adjustable exhaust-column bridge, yet it isevident that other forms of apparatus may be 'employed for this purposeor that such exhaust-column bridge may be operated manually, and while Ihave shown and described a preferred means for automatically admittingsteam to the cylinder controlling the operation of such adjustableexhaust-column bridge other means for this purpose may he employed-as,for example, a slidevalve or a triplev valve.

vMy invention is susceptible of many modifications and many 'changes inconstruction and form of parts without departing from the spiritthereof.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, isd

l. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge within saidexhaust-column, substantially as and for the purposes specified.

Q. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge within saidexhaust-column, and means lfor adjusting said exhaust-column bridge,substantially as and for the purposes specified.

3. In a variable-exhaust mechanism, the combination with anexhaust-column, o f an adjustable exhaust-column bridge within saidexhaust column, and pressure controlled IXO means for automaticallyadjusting said exhaust-column bridge, substantially as and for thepurposes specilied. l Y

4. In a variable-exhaust mechanism, the combination with anexhaust-column, of an exhaust-column bridge Within said'exhaustcolumn,said bridge havingupwardly-diverging walls, substantially as and for thepurposes specilied.

5. In a variable-exhaust mechanism, the combination with anexhaust-column, of an exhaust-column bridge within said exhaustcolumn,said bridge comprising a plurality of relatively movable sections,substantially as and for the purposes specified.

6. In avariable-exhaust mechanism, the combination with anexhaust-column, of an exhaust-column bridge within said exhaustcolumn,said bridge comprising aplurality of resilient sections, substantiallyas and for the purposes specified.

7. In a variable-exhaust-mechanism, the

'combination with an exhaust-column, of an exhaust-column bridge within.said exhaustcolumn, said bridge adapted tov vary the exhaust area ofsaid exhaust-column by-a variation in form of the saidexhaust-eolumn'brid ge, substantially as and for the purposes specitied.

8. In a variable-exhaust mechanism, the combination with anexhaust-column, 'of an adjustable exhaust-column bridge Within. saidexhaust-column, said bridge comprising a plurality of sections normallytending to approach each other, substantially as and for the purposesspecilied.

9. In a variable-exhaust mechanism, the combination with anexhaust-column, of an exhaust-column bridge Within said exhaustcolumn,said bridge comprising a plurality of relatively movable sections, andmeans for moving said sections relatively, substantially as and forthepurposes specified.

10. In a variable-exhaust mechanism, theA combination with anexhaust-column, of an exhaust-column bridge Within said exhaustcolumn,said bridge comprising a plurality of relatively movable sections, and acam for moving said sections relatively, substantially as and for thepurposes specified.

11.v In a variable-exhaust mechanism, the

combination with an exhaust-column, of an exhaust-column bridge Withinsaid exhaustcolumn, said bridge comprising a plural-ity of relativelymovable resilient sections, and means formoving said sectionsrelatively, substantially as and for the purposes specified.

12. In a variable-exhaust mechanism, the` combination with anexhaust-column, of an exhaust-column bridge within said exhaustcolu mn,said bridge comprising a plurality of. relatively movableresilientsections, and a cam for moving said sections relatively, sub.-stantially as and for the purposes specified.

lf3. In a variable-exhaust mechanism," the combination with anexhaust-column having` BEST AVAlLABLE COF` a choke, of means Within saidexhaust-columi for varying the exhaust area of said exhaust column atthe choke, substantially as and fo: the purposes specified.

14C. In an exhaust mechanism, the combina tion with an exhaust-columnhavingupwardly convcrgingwalls, of an exhaust-columnbridge within saidexhaust-column, said bridge having upwardly-divergi ng walls,substantially as and for the purposes specified.

15. In an exhaust mechanism, the combinaupwardly-converging walls, achoke and di- Verging walls above said choke, of an adjustable.exhaust-column bridge comprising a plurality of resilient sectionsterminating adjacent to said choke, substantially as and for thepurposes specified.

18. In a. variable-exhaust mechanism, the combination with anvexhaust-column having .upwardly-converging walls, a choke and di vergingWalls above saidv choke, of an' adjustf able exhaust-column bridgecomprising a plu- .rality of resilientsections terminating adjacent tosaid choke,\andv a cam adapted to actuate said resilient sections,substantially as and for the purposes specilied. a. 19. In avariable-exhaust mechanism, the

- combination With an exhaust-column. having upwardly-'converging Walls,a choke land divergingwalls above said choke, of an adjustableexhaust-column bridge comprising a plurality of relatively movablesections terminating adjacent to said choke, and means for movingsaidsections relatively, substantially as and for the purposes specified.

20. In a variable-exhaust mechanism, the combination With anexhaust-column, of i an exhaust-columnl bridge within saidexhaustcolumn, said bridge comprising a4 plurality of relativelymovableY sections, and means for automatically moving saidsectionsrelatiwly, substantially asand for the purposes specified. 21.In a variable-exhaust mechanism, the combination with an exhaust-column,of an exhaust-column,bridge within said exhaustcolumn, said bridgecomprising a plurality of Arelatively movable resilient sections, and

II.I

22. In avariable-exhaust mechanism, the )mbination with anexhaust-column, of an xhaust-column bridge within said exhaustolumn,said bridge adapted to vary the exaust area of said exhaust-column, andmeans or automatically actuating said exhaust-colmn bridge to vary saidexhaust area, subtantially as and for the purposes specified.

23. In a variable-exhaust mechanism, the ombination with anexhaust-column, of an :xhaust-column bridge within said exhaustzolumn,said bridge adapted to vary the exiaust arca of said exhaust-column, acylinder, t piston within said cylinder, means for automaticallyactuating said piston, and devices interposed between said piston andsaid exhaust-column bridge for actuating the latter, substantially asand for the purposes specified.

24. In a variable-exhaust mechanism, the

combination with an exhaust-column, of an adjustable exhaust-columnbridge within said exhaust-column, a cylinder, a piston within saidcylinder, pressure-controlled means for actuating said piston, means forlimiting the length of ystroke of said piston, and devices interposedbetween said piston and said ex haust-column bridge for actuating thelatter, substantially as and for the purposes specified.

25. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge within saidexhaust-column, a cylinder, a piston within said cylinder, ahigh-pressure valve controlling a cylinder-port, a low-pressure valvecontrolling a cylinder-port, a diaphragm` acting upon said high-pressurevalve, a diaphragm acting upon said low pressure valve. and meansinterposed between said piston and said "ei'ustcolumn bridge foractuating the latter, `substantially as and for the purposes specified.

26. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge Within saidexhaust-column, a cylinder, a piston within said cylinder, ahigh-pressure valve controlling a cylinder-port, a low-pressure valvecontrolling a cylinder-port, and means interposed between said pistonand said exhaust-column bridge for actuatingthe latter, substantially asand for the purposes specilied. y

27. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge within saidexhaust-column, a cylinder, a piston within sail "ylinder, ahigh-pressure valve controllinga cylinder-port, a low-pressure valvecontrolling a cylinder-port, springs acting upon said valves, and meansinterposed between said piston and said exhaust-column bridge foractuating the latter, substantially as and for the purposes specified.

28.In a variable-exhaust mechanism, the combination with anexhaust-column, of an BEST AVAILABLE COF" adjustable exhaust-columnbridge comprising a plurality ot' relatively movable Vsections withinsaidexhaust-column, a cam interposed between said sections and adaptedto actuate the same, acrank adapted to actuate said cam, acylinder,apiston within said cylinder, means for automatically actuating saidpiston, and a reach-rod flexibly connected to said crank and saidpiston, substantially as and for the purposes speciied.

29. Ina variable-exhaust mechanism, the` vcombination with anexhaust-column, of an adjustable exhaust-column bridge comprising aplurality oi' relatively movable sections within said exhaust-column, acam interposed between said sections and adapted to actuate the same, acylinder, a piston within said cylinder, means forlimiting the stroke ofsaid piston, means for automatically actuating said piston, and devicesinterposed between said piston and said cam for actuating the latter,substantially as and for the purposes specified.

30. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge comprisingaplurality of relati vcly movable sections within said eXhaust-cplumn, acam interposed between said sections and ad apted to actuate the same, acrank adapted to actuate said cam, a cylinder. a movable member withinsaid cylindex', a high-pressure valve controlling acylinder-port, alow-pressure valve controlling a cylinder-port, diaphragme for saidvalves, springs acting upon said diaphragms, means for graduating thepressure of said springs upon their respective diaphragms, and meansinterposed between said movable member and said cam for actuating' thelatter, substantially as and for the purposes specitied.

31. In -a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge comprising aplurality of relatively movable sections within said exhaust-column, acylinder, a piston within said cylinder, a high-pressure valvecontrolling a cylinder-port, a low-pressure valve controlling acylinder-port, diaphragms for said valves, means for transmittingpressure to said diaphragms, and means interposed between said pistonand said exhaust-column bridge for actuating the latter, substantiallyas and for the purposes specified.

32. In a variable-exhaust mechanism, the combination with anexhaust-column, ot' an adjustable exhaust-column bridge within saidexhaust-column, a cylinder, a piston within said cylinder, ahigh-pressure valve controlling a cylinder-port, a low-pressure valvecoutrolling a cylinder-port, diaphragms for said Valves, springs actingupon said diaphragme, ln'eans Vfor grai'lllating' the pressure of saidsprings upon their respective diaiiihragms, means for transmittingpressure to said diaphragms, and devices interposed between said IOO IIO

IIS

sEsT AVAILABLE cee` piston and said exhaust-column bridge for actuatingthe latter, substantially as and for the purposes specified. l

33. In La variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge comprising aplurality of resilient. sections Within said eX- haust-column, acylinder, a piston Within said cylinder, means for automaticallyactuating said piston, and means interposed betweensaid piston and saidexhaust-column bridge for actuating the latter, substantially as and forthe purposes specified.

34. In a variable-exhaust mechanism, the combination with adraft-regulator, of a high and low pressure cylinder, and independenthigh and low pressure valves operative to control the admissionofpressure to the said cylinder, substantially as and for the purposesspecified. l

35. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge, a high and lowpressure cylinder, independent high and low pressure valves operative tocontrol the ad mission of pressure to the said'cylinder, and meansoperative by the. admission of pressure to the cylinder for actuatingsaid adjustable bridge, substantially as and for the purposes speciied.

36. In a variable-exhaust mechanism, the combination with anexhaust-column, of an adjustable exhaust-column bridge, a source ofpressure, and means operated by variations in said pressure foractuating said exhaustcolumn bridge, substantially as and for thepurposes specified.

37. In a variable-exhaust mechanism, the combination with anexhaust-column, of an ad justable exhaust-column bridge, a cylinder, asource of pressure connected to said cylinder, and means actuated byvariations in said pressure for operating said exhaust-column bridge,substantially as and for the purposes specified.

38. In a variable-exhaust mechanism, the

40. In a variable-exhaust mechanism, the

combination with an exhaust-column, of an adjustable exhaust-columnbridge having a closure for the top thereof, and means for adjustingsaid exhaust-column bridge, substantially as and for the purposesspecified.

41. In a variable-exhaust mechanism, the combination with anexhaustcolumn, of an exhaust-column bridge comprising a plurality ofrelatively movable sections having their upper ends engaging each otherto form a closure for the top of said exhaust-column bridge,substantially as and for the purposes specified.

, 42. In a variable-exhaust mechanism, the combination with anexhaust-column, of an exhaust-column bridge comprising a plurality ofresilient sections having their upper ends 'bent inwardly to form aclosure for the top of said exhaust-column bridge, substantially as Aandfor the purposes specified.

43. An exhaust-column bridge comprising v a plurality of resilientsections provided with y CHARLES L. PAGENHART.

Witnesses:

OTIS ELLIsoN, H. C. CARROLL.

